Why You Don't Really Need To Warm Up Your Car In Winter

Nathan Giannini , Katherine Biek

1:50 PM, Feb 13, 2015

Photo Credit: Getty Images / Joe Raedle

We totally get it. When there's snow on the ground, temperatures are below freezing and the wind chill is even lower than that, it's really nice to have your car already toasty before you jump in in the morning.

Idling your car in the driveway to let it warm up might keep it warm, but it's not only unnecessary, it's expensive, it's bad for the environment and really, it's kind of unsafe.

News reports from all over the country show thieves are targeting cars left idling in the driveway, unlocked and with the key in the ignition.

"These new cold-weather crooks can spot that exhaust from the street and pounce, already striking nationwide from Texas to California, Michigan to Kansas," NBC reported.

Police call these unattended vehicles "puffers" for the very obvious, very visible puffs of smoke coming from the car's exhaust. Authorities say this is really an unnecessary risk because the best way to warm your car up is to drive it. The U.S. Department of Energy recommends idling for about 30 seconds before driving off gently. The engine will warm up faster if it's being driven, meaning the heat will turn on sooner, and you'll save on fuel and reduce emissions.

And depending on where you live, idling might actually be illegal. There are currently 31 states with anti-idling laws of varying severity.

And for good reason. A 2009 Vanderbilt University study found idling of all kinds accounted for 1.6 percent of all U.S. greenhouse gas emissions and costs consumers $5.9 billion per year.